The scope of the invention more specifically relates to packaging systems comprising a packaging module for performing at least two operations on flexible containers arranged in a row which are conveyed in a suspended manner from an endless conveyor element, such as a chain conveyor, for example. The only known example of a packaging module of this type is described in European patent application No. 11382096.
These packaging modules must be fed with empty formed containers. Many proposals for manufacturing empty flexible sachet-type containers or containers of the types having the capacity to remain upright, also called doypack, producing containers that are open at the top and ready to be manipulated, for example, for their subsequent filling and sealing, from one or several bands of flexible, heat sealable material, are known. The containers obtained must be subjected to a transfer operation for feeding the conveyor element of the packaging module. This transfer becomes complicated when the produced empty containers are supplied intermittently, for example, in twos, while the conveyor element moves forward continuously.
Carousel packaging machines use transferring devices which link the container forming modules with the packaging modules and which are arranged to that end between both modules.
Therefore, transferring devices comprising groups of clamps performing alternative back and forth movements between a container production module and a packaging module, for example, are known. These groups of clamps are capable of seizing respective containers located in a static standby or delivery position of the production module and giving them a linear trajectory coinciding with a linear section of the trajectory followed by the container holding means provided to the carousel for releasing them once the containers are secured by said holding means and recovering their starting position to repeat the same operation again.
One objective of the invention is a method and a device which simplifies this transfer operation.
Another objective of the invention is a method and a device which allows reducing the surface necessary for carrying out this transfer operation, and even allows, according to one embodiment, eliminating the surface occupied up until now by the transferring device linking a forming module with a packaging module.
In addition to the operation performed by the transferring devices, the use of an endless conveying element in a packaging module also requires performing the operation of delivering or releasing the end containers. This operation sometimes requires a second transferring device capable of seizing the containers which are conveyed by the conveyor element and arranging them in a delivery location.
One objective of the invention is a method and a device which simplifies this operation, and even allows, in an embodiment variant, performing the two transfer operations, the operation of feeding the endless element and the operation of unloading the endless element by means of a single device.
On the other hand, as suggested above, the container production modules supply the containers intermittently, this means that in the standby position there is a reserve of containers or that these containers remain static while the endless conveyor element moves forward continuously. Likewise, when removing the containers from the conveyor element, they must be slowed down prior to their delivery to prevent container imperfections. Therefore, another objective of the present invention is a device which, in addition to achieving the main objectives of the invention, may be capable of seizing one or more containers at the same time in a static standby position and transferring them to the conveyor element and at the same time removing containers from this conveyor and releasing them in a delivery position with very little or no inertia, all this without changing the packaging module productivity.
Finally, the device must be capable of conferring speed and trajectory coinciding with that of the endless conveyor element to the seized containers and of separating them from one another by a distance equivalent to the distance separating the holding means of each container in the conveyor element.